Combine flour, baking powder, cinnamon, soda, and salt. Set aside. In mixing bowl, beat together eggs, pumpkin, sugar, and oil. Add flour mixture. Beat well. Stir in pecans. Spread in ungreased 15x10x1 inch baking pan. Bake in 350° oven for 25-30 minutes or until toothpick inserted in center comes out clean. Cool on wire rack.
For Cream cheese frosting, in a bowl beat together cream cheese, butter and vanilla until fluffy. Gradually add sifted powdered sugar, beating until smooth. Frost cooled bars. Sprinkle with additional chopped pecans, if desired. Cut into squares.
